I have:

On column A
Pending
Paid
Cancel
Refund
NSF
Hold

I have:

On column B
$250
$300
$100
$250
$300
$100


The "Paid" and "Pending" ones would need to stay as positive values but the rest as my formula below would need to be negative. I tried to do a conditional format to make any positive change to a negative amount if the words on Column A are "Cancel, Hold, NSF or Refund". This is what I did so far but of course it doesn't work. Any ideas?

=if(or(a:a="Cancel",a:a="NSF",a:a="Refund",a:a="Hold")b:b=*-1))